Furthermore , shear type is simple shear - dominated at the early stage by analysis of wk from the method of polar mohr and pure shear component increases at the late stage by the methods of ecc . much synthetic extensional crenulation cleavage ecc is found in mylonitic rocks zone 不同方法求得运动学涡度wk介于0 . 453 ? 0 . 809间,表现为一般剪切作用类型,其中早期为以简单剪切组份为主、晚期为以纯剪组份为主的一般剪切作用类型。